1. Field of the Invention
This invention relates to the art of firefighting equipment.
More particularly, the invention relates to a nozzle for dispensing liquid from a fire hose.
In a further and more specific aspect, the instant invention concerns a nozzle having a valve that acts simultaneously to prevent excessive pressure build-up in the nozzle, and to create a curtain of liquid for cooling the nozzle operator and the surrounding environment.
2. Description of the Prior Art
Firefighters who operate hand-held nozzles are at constant risk of injury from the reaction forces generated when high-pressure liquid is discharged from those nozzles. Very often these forces cause whipping motions or other unwanted movements that can cause the firefighter to drop the nozzle, lose balance, and even be thrown off a ladder or a ledge.
In addition to the danger presented by high reaction forces, the firefighter must cope with the extremely high temperatures created by the fire itself. Not only is the air around the fire uncomfortably hot, but any equipment, vehicles, or structures in the vicinity also heat up, and can scorch or scald any firefighters or bystanders who inadvertently come into contact with these items. Accordingly, there is a need for a cooling system that can reduce the ambient temperature of the fire scene.
Various attempts have been made to solve the problem of high reaction forces. For instance, engine-driven pumps are often controlled by governors which respond to increases in discharge pressure by decreasing the rpm of the engine. In addition, some nozzles have trigger-operated valves where the strength of the operator's grip determines the discharge pressure. However, none of the existing systems are foolproof, and many are expensive.
The problem of high ambient temperature is alleviated to an extent by certain nozzles that incorporate a “fog generation” feature that allows them to emit a conical spray of evenly distributed water droplets. This spray spreads over a relatively wide area, forming a cool, protective shroud in front of the nozzle operator. However, because this spray is forwardly directed, it does little to cool the areas directly alongside or behind the operator.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.